var Combinatorics = require('js-combinatorics');

var a = [
  "opportunist",
  "planner",
  "scientist",
  "hacker",
  "networker",
  "friend",
  "griefer",
  "politician"
];


function hasFourMembers(array) {
  return array.length === 4;
}



cmb = Combinatorics.permutationCombination(a);
var cmbArray = cmb.toArray();
var filtered;
setTimeout(function(){
 filtered = cmbArray.filter(hasFourMembers);
console.log(filtered.length); 


require('fs').writeFile(

    './my.json',

    JSON.stringify(filtered),

    function (err) {
        if (err) {
            console.error('Crap happens');
        }
    }
);
},50)